Lightroom: JPG export of all photos maintaining the folder structure

It would be nice to be able to export all 30.000 photos to JPG in a single step so, that the folder structure is maintained (a folder structure that is identical to the original would be created for the export). This way I could get an archival copy of all my photos, which would be easy to use after 30 years, by my children.

And another option without plugins - export into same folder as original, or if you use DNG, simply update embedded previews (granted, none of us really knows how much future-soft will be able to auto-handle DNG previews)...